Given below are two statements: one is labelled as Assertion A and...

Pascal's law states that the pressure in a closed incompressible fluid is transmitted equally in all directions.

The formula for pressure is given by

$P = \dfrac{F}{A}$

When a toothpaste is squeezed let the pressure transmitted by $P$. At the mouth of the toothpaste the pressure will also be equal to $P$ due to Pascal's law. The pressure applied to the tube is transmitted equally throughout the toothpaste. When the pressure reaches the open end, it forces toothpaste out through the opening. Hence, both $A \text{ and } R$ is correct and $R$ is correct explanation for  $A$.